How do i fix my central Vacuum system that is not turning on?

A guide to repairing the following built in vacuum systems.  Aerus Electrolux, AirVac, Allegro, Beam, Beam Serenity Series, Bissell, Cana-Vac Signature Series, CanaVac, Central Vac International (CVI), Central Vacuum Stores, Centralux, CycloVac, Cyclovac H215, Dirt Devil, Drainvac, Duovac, DynaVac, Electrolux, Electrolux Oxygen, Eurovac, Eureka, Honeywell, Hoover, H-P Products, Hypervac, Imperium Central Vacuums, InterVac, Lindsay Manufacturing, MaxVac Central Vacuums, MD Central Vacuum, Miele, MVac Central Vacuums, Nutone, OVO Central Vacuums, Panasonic, PowerStar, Prolux, Pullman-Holt, PurVac, Quest Central Vacuums, Riccar, Saniflo, Sanitaire, Sebo, Sereniti Central Vacuums, Simplicity Vacuums, Smart Central Vacuums, SpeedyVac Central Vacuums, Star Central Vacuums, Thoro-Vac, Titan, Titanium Central Vacuums, Tornado, Trovac, Trovac Industries, TurboCat Powerhead, Vacuflo, Vacumaid, VacuSweep, Valet, VACUFLO Filtered Cyclonic, VACUFLO True Cyclonic, Vroom Central Vacuums, ZVac.